Warner Bros. along with GameInformer have confirmed the next game in the Batman Arkham series, Batman: Arkham Origins. Rocksteady will not be developing this Arkham title; instead, that honor goes to Warner Bros. Games Montreal.
Arkham Origins is set to release on October 25, 2013 for all current-gen platforms (Xbox 360, PlayStation 3, PC, and Wii U). As it sounds, it tells the secret origin story of Batman, the one no one has heard a thousand times over. Batman is young, rather inexperienced, and we'll get to witness his first encounters with several villains, including Deathstroke.
The 3DS and the PlayStation Vita will get their own Batman: Arkham Origins game, Blackgate, which has been descried as a "2.5 Metroid-style game" with a completely different story that takes place after the console game. Blackgate is being developed by Armature Studio, the developer who brought the Metal Gear Solid HD Collection to the Vita.